The present invention relates generally to apparatus for accumulating a traveling length of web-like material, such as textile fabric, and relates more particularly to apparatus of such type which operates to form the accumulated material in succeeding festoons.
Apparatus of the aforementioned type are commonly employed in various industries to temporarily accumulate a traveling length of web-like material during a predetermined interruption in the downstream travel of the material so that the upstream delivery of the material can continue uninterrupted so that the production efficiency or capacity of the particular manufacturing operation can be optimized. For example, it is common in various textile fabric-producing and fabric-treating operations to wind the fabric into roll form as the fabric completes the operation. When it is periodically necessary to doff the wound roll of fabric upon reaching its maximum capacity, it is highly desirable not to interrupt the fabric-producing or fabric-treating operation which is delivering the fabric to the roll. Accordingly, it is common practice to position a fabric accumulating apparatus or device between the roll-winding location and the upstream fabric-producing or fabric-treating operation to receive the continuing delivery of fabric while the doffing operation is carried out and until the winding of a new fabric roll can be initiated.
The foregoing web accumulating procedure has functioned suitably in practice for some time. However, as the production speeds of conventional textile fabric-producing and fabric-treating equipment has increased in recent years, the limited capacity of conventional fabric accumulating apparatus has begun to effectively limit the full realization of the maximum production capacity of modern textile equipment. For example, one conventional form of fabric accumulating device still in use in the textile industry is a so-called "horse" which basically comprises an elongate saddle over which a traveling fabric may be laid back and forth in a plaited manner. The disadvantage of utilizing a "horse" for accumulating fabric is that, as the fabric accumulates, the increasing weight of the fabric is borne by the initially-laid plaits of fabric, and thus the total capacity of a "horse" is limited, particularly with fabrics such as plush or pile fabrics whose surface may be sensitive to crushing forces.
One conventionally-available alternative is festooning-type fabric accumulating apparatus wherein a series of uniformly spaced festoon support bars are affixed to an endless conveyor arrangement which is selectively driven to allow fabric to be accumulated in successive festoons depending between the succeeding support bars. However, this type of apparatus also has inherent limitations as to the maximum capacity for accumulating fabric without increasing the size of the festooning apparatus, either vertically or horizontally.
Given the capacity limitations of conventional "horses" and festoon-type accumulators, the normal time periods required for performing a typical fabric roll-doffing operation, and the relatively high production capacities of many conventional textile fabric producing machines, it can occur when the fabric-producing or fabric-treating machine is operating at its full capacity that a conventional "horse" or festoon accumulator will approach or even reach its full capacity within the amount of time required to accomplish a doffing operation, leaving little or no margin for error or delay in the doffing operation.